Updated June 6, 2017: Updated with a statement from Microsoft on the matter.

Original Story: Kaspersky Lab has moved to file an antitrust complaint against Microsoft in Europe over what it sees as unfair practices to promote Windows Defender over competing products in Windows 10. In a blog post, co-founder of the Russian firm, Eugene Kaspersky, lays out several complaints that, he says, highlight "questionable tactics" on Microsoft's part to give its own antivirus solution an unfair advantage (via The Verge).

From Kaspersky:

We see clearly – and are ready to prove – that Microsoft uses its dominant position in the computer operating system (OS) market to fiercely promote its own – inferior – security software (Windows Defender) at the expense of users' previously self-chosen security solution. Such promotion is conducted using questionable methods, and we want to bring these methods to the attention of the anti-competition authorities.

Kaspersky's complaints include accusations that Microsoft removes its software from users' PCs when they upgrade to Windows 10, turning to Windows Defender in its place. The stated reason is compatibility issues, but Kaspersky claims Microsoft doesn't afford third-party antivirus developers enough time with an update's RTM release to update their software ahead of a broad rollout.

In its complaint, Kaspersky says it is seeking to stop Microsoft from "misleading and misinforming" users in order to keep security software "on a level playing field" on the Windows Platform.

For its part, a Microsoft spokesperson reached out to Windows Central with the following statement:

Microsoft's primary objective is to keep customers protected and we are confident that the security features of Windows 10 comply with competition laws. We're always interested in feedback from other companies and we engage deeply with antimalware vendors and have taken a number of steps to address their feedback. We reached out directly to Kaspersky a number of months ago offering to meet directly at an executive level to better understand their concerns, but that meeting has not yet taken place.